Concept:The reaction between a carbonyl compound and a primary amine derivative (like hydroxylamine, hydrazine, etc.) proceeds via a two-step mechanism.
Formula:$$ >C=O + H_2N-G \rightleftharpoons >C(OH)(NH-G) \longrightarrow >C=N-G + H_2O $$
Solution:- Step 1 (Addition): The nucleophilic nitrogen atom attacks the electrophilic carbonyl carbon, forming a tetrahedral carbinolamine intermediate.
- Step 2 (Elimination): The intermediate is unstable and rapidly eliminates a molecule of water to form a stable carbon-nitrogen double bond.
- Because the process requires both of these steps, it is formally classified as an Addition-Elimination reaction.
Why other options are incorrect:Nucleophilic addition is only half the story; it ignores the water elimination. Electrophilic addition occurs in alkenes. Nucleophilic substitution typically involves replacing a leaving group attached to an \( sp^3 \) hybridized carbon, which is not the case here.
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